L-glutamine is an amino acid widely used as medicines such as therapeutic agents of gastroenterologic disorders, potentiators of liver and brain functions, immuno-enhancement agents, and therapeutic agents of gastric ulcer and alcoholism, etc., cosmetics such as moisturizers, etc., and health foods such as sports nutrients and nutrients for patients, etc.
According to the prior art, L-glutamine was obtained from sulfaguanidine-resistant strains (Japanese Patent, Laid-Open No. Sho53-17675), azaserine-resistant strains (Japanese Patent Laid-Open No. Sho55-148094) penicillin-sensitive strains (Japanese Patent Laid-Open No. Hei04-088994), tyrosine-glutamic acid (tyr-glu)-resistant strains (Japanese Patent Laid-Open No. Hei02-186994) and the like.